1. Field of the Invention
The present invention is a technique effectively applied to a door opening/closing mechanism in an autoloading device for a magnetic tape cartridge, etc.
2. Description of the Related Art
This type of door opening/closing mechanism in the prior art is shown in FIG. 6.
FIG. 6 is a structural view showing a door opening/closing mechanism used for an autoloading device for a magnetic tape cartridge, etc. A device body 21 includes a one-way opener type door element 22 which is closed to seal processing space 27 in the device body 21.
In this type of autoloading device, if the door element 22 is opened during the processing, a cartridge loaded in the processing space 27 may be jammed or the order of reading data contained the cartridge may change, to thereby cause any failure on the data processing.
In order to avoid such a failure, the door element 22 must be prevented from opening/closing, and the door element 22 must be reliably locked. Therefore, a mechanism has been required to reliably detect the closing state of the door element 22.
In the prior art, the device body 21 includes a photosensor 25 and microswitch 26 which are used in combination with a first detection flag 23 and a second detection flag 24 which are attached to the door element 22 side for the detection. More specifically, when the door element 22 is closed, first, the detection flag 24 is pressed onto the microswitch 26 to be turned on. Then, this closing state is judged to continue or not depending upon whether or not the photosensor 25 senses the first detection flag 23.
However, since there is a two-step detection mechanism, it may be complicated to identify the closing state, and another lock mechanism with different arrangement is separately required to thereby make the overall structure complicated. In addition, even in the state where the door is not precisely locked (half-opened), the photosensor 25 may possibly sense that the door element 22 is closed.
The present invention has been made in view of the above-stated problems, and it s object is to provide a technique reliable to lock a door element and detect its state.
According to the present invention, a pressing unit is mounted to a part of a door element so that it may press in the closing direction independent ly of the door body, and latch means is mounted to the mating part of the door element so that it may be engaged with a distal end of the pressing unit at a distance less than a predetermined spacing to finely move the door element. A projecting part projecting toward the mating part is mounted to the pressing unit. The mating part includes resilient means acting to repel a force of the projecting part influenced in the direction of the mating part, and a switching element operable to detect the closed state of the door element when the projecting part presses the resilient means with more than a predetermined pressing force.
With such a switching structure that the door element can be finely moved even in a latched state and detected with more than a predetermined force of pressing a pressing unit, the locking of the door element and the detection mechanism can be functionally separated, thereby making it possible to reliably lock the door element and detect its closed state.